Felix Thoemmeshttps://felixthoemmes.github.io/
Recent content on Felix ThoemmesHugo -- gohugo.ioen-USWed, 27 Jun 2018 00:00:00 +0000The front-door criterion in linear, parametric modelshttps://felixthoemmes.github.io/blog/the-front-door-criterion-in-linear-parametric-models/
Wed, 27 Jun 2018 00:00:00 +0000https://felixthoemmes.github.io/blog/the-front-door-criterion-in-linear-parametric-models/Inspired by a recent discussion on SEMNET, I decided to publish a short blog post about the front-door criterion. The front-door criterion was developed by Judea Pearl, as a means to identify and estimate a causal effect in the presence of unobserved confounders.
Consider the following DAG (directed acyclical graph) in which a treatment X has an effect on an outcome Y. This effect however cannot directly be estimated without bias, because there is an unobserved confounder U.Kelly criterionhttps://felixthoemmes.github.io/blog/kelly-criterion/
Mon, 18 Jun 2018 00:00:00 +0000https://felixthoemmes.github.io/blog/kelly-criterion/I enjoyed looking at the probabilistic model of world cup matches over at fivethirtyeight and was wondering how one would fare in terms of sports betting using the predictions from Nate Silver and Jay Boice. As a disclaimer: I did not bet any money at all, all of the below is purely theoretical.
So here is what I did: for each game, I pulled the winning probabilities from fivethirtyeight and the corresponding odds from online bookmakers.Balance checkshttps://felixthoemmes.github.io/blog/balance-checks/
Mon, 04 Jun 2018 00:00:00 +0000https://felixthoemmes.github.io/blog/balance-checks/A recurring discussion on Twitter and other social media is whether one should or should not check baseline covariates for balance in a randomized experiment. The discussion comes in various flavors, sometimes focusing on whether the very act of balance checks are meaningful, or whether randomization actually is or is not expected to yield balance, and whether something should or should not be done about unbalanced covariates. Stephen Senn has written a paper on this called “Seven myths of randomisation in clinical trials” (http://onlinelibrary.Non-transitive dicehttps://felixthoemmes.github.io/blog/non-transitive-dice/
Mon, 24 Jul 2017 00:00:00 +0000https://felixthoemmes.github.io/blog/non-transitive-dice/About ten years ago I bought myself a set of non-transitive dice. I have occasionally used them in class, but I am afraid that I am more excited about these dice than the average student. The main idea behind non-transitive dice is that out of a set of dice (and under repeated rolls), one die (A) will on average show a higher value than another die (B), and therefore beat it in a game in which the highest roll wins, but at the same time this winning die (A) will be dominated by another die (C), which itself loses to the loser of the first competition (B).Rounding in the age of statcheckhttps://felixthoemmes.github.io/blog/rounding-in-the-age-of-statcheck/
Mon, 05 Jun 2017 00:00:00 +0000https://felixthoemmes.github.io/blog/rounding-in-the-age-of-statcheck/I recently chatted with a colleague whose work was flagged on PubPeer by the statcheck bot that has been scraping the web last year or so. Her reaction - which I believe is pretty typical - was mild annoyance. To her (and I believe many others) it felt a bit pedantic to be flagged what was essentially a rounding error. She feared that such a flag may create a false impression that the work is a “false positive”, and that people jump to conclusions when they see a statcheck error.Keeping exploratory and confirmatory analyses strictly separatehttps://felixthoemmes.github.io/blog/keeping-exploratory-and-confirmatory-analyses-strictly-separate/
Sat, 27 May 2017 00:00:00 +0000https://felixthoemmes.github.io/blog/keeping-exploratory-and-confirmatory-analyses-strictly-separate/Recently Wang et al. published a paper in the Journal of Experimental Psychology on pre-registered analyses and the use of covariates in un-registered, exploratory, post-hoc analyses, specifically in the context of randomized experiments 1.
I am in 100% agreement with the vast majority of what the authors have to say, and also with the general sentiment of the paper, which I summarize as follows:
1.) Pre-register your analyses and report the results of your pre-registration fullyHello World (blog roll)https://felixthoemmes.github.io/blog/hello-world-blog-roll/
Fri, 12 May 2017 00:00:00 +0000https://felixthoemmes.github.io/blog/hello-world-blog-roll/As Rich Lucas recently said, it seems somewhat anachronistic to start a blog in 2017, but here I am… doing it anyway.
Well, I worry that starting a blog in 2017 is a bit like creating a myspace page in 2010, but here goes: https://t.co/12RevfumqL
&mdash; Rich Lucas (@rlucas11) May 2, 2017 The main reason why I started this blog was probably because I enjoy reading other blogs. So instead of doing the obligatory blog roll section, I will simply write about some blogs that I like.